The taking of venous blood samples is quite well-known. The taking of arterial blood samples has also become recognized as important. In patients suffering from diseases of the lungs or heart, it is important to know the oxygen content of the blood. This content is determined by blood gas analysis of arterial blood. It is essential, therefore, that arterial blood, rather than venous blood be withdrawn for such analysis. Heretofore, such blood was obtained using a conventional hypodermic syringe. The problem is that it is difficult to tell whether the scarf of the needle is in an artery or a vein. Arteries are generally deep within the body tissue, making the determination by feel or sight difficult. This is particularly true in obese patients and infants. If the intended arterial blood sample is not arterial blood, another attempt must be made to the discomfort of the patient. Also, in certain types of cases, important time is lost in the diagnostic procedure.
The present invention provides a dependable way of taking arterial blood samples and it is believed that the device of this invention represents a major advance in the art. Its disadvantages and benefits will be evident to those skilled in the art.